small world graph implementation

samllworldgraph.py

from RandomGraph import RandomGraph,show_graph
from Graph import *
import string
from random import random, choice

class SmallWorldGraph(RandomGraph):

    def rewire(self, p):
        vs = self.vertices()
        for i, v in enumerate(vs):
            for e in self.out_edges(v):
                if random() <= p:
                    without_v = vs[:i]+vs[i+1:]
                    w = choice(without_v)
                    self.remove_edge(e)
                    e = Edge(v,w)
                    self.add_edge(e)
                    
def main(script='',n=20,k=4,p=0.01):
    n,k,p = int(n),int(k),float(p)
    labels = string.lowercase + string.uppercase + string.punctuation
    vs = [Vertex(c) for c in labels[:n]]
    g = SmallWorldGraph(vs)
    g.add_regular_edges(k)
    g.rewire(p)
    show_graph(g)
    
if __name__ == '__main__':
    import sys
    main(*sys.argv)